There has been a semiconductor integrated circuit apparatus in which current adjusting Metal Oxide Semiconductor Field Effect Transistors (MOSFETs) are attached to output circuits, respectively, that have Low Voltage Differential Signal (LVDS) configurations. In the semiconductor integrated circuit apparatus, one of the output circuits is used as a dummy output circuit and a termination resistor is connected to an output terminal of the dummy output circuit. A control signal of the current adjusting MOSFET connected to the dummy output circuit is generated by comparing high level and low level output from the output terminal and reference high level and low level, respectively, so that output level of the dummy output circuit become designated output levels. In the semiconductor integrated circuit apparatus, the control signal is supplied to the rest of the current adjusting MOSFETs of the output circuits in order to control currents of the output circuits automatically (for example, see patent document 1).
Moreover, there has been a parameter correcting circuit embedded in a semiconductor integrated circuit. According to the parameter correcting circuit, the semiconductor integrated circuit includes a current supply circuit, a variable parameter, a plurality of switch circuits, a voltage detect circuit and an adjusting circuit which adjusts a parameter value of the variable parameter. A reference parameter is connected to one of the switch circuits of which the parameter value has been known in advance, and the switch circuits switch electrical connection among the current supply circuit, the reference parameter, the variable parameter and the voltage detect circuit. The voltage detect circuit detects voltages of the reference parameter and the variable parameter in a case where currents are supplied from the current supply circuit to the reference parameter and the variable parameter, respectively. The adjusting circuit adjusts the variable parameter and the parameter value based on the voltages of the reference parameter and the variable parameter detected by the voltage detect circuit (for example, see patent document 2).
However, the conventional semiconductor integrated circuit apparatus does not include adjusting equipment which adjusts a termination resistor at a receive (Rx) side.
Moreover, in the parameter correcting circuit, a first terminal of a variable resistor element is connected to a mirror circuit, and a second terminal of the variable resistor element is grounded. Since the variable resistor element is grounded as described above, it is difficult to adjust a resistance value of the variable resistor element at a receiving circuit side of a transceiver circuit in a case where an arbitrary termination voltage which is different from a power source voltage of the transmitting circuit is supplied to the variable resistor element. In the transceiver circuit, a transmitting circuit and the receiving circuit are coupled in an alternating current coupling configuration.